Scaffold winch



May 15, 1951 R. H. BENSON ET AL sc'A'rFoLn wmcn 3 sheets sheet 1 Filed March 8, 1950 INVENTORS Ell 156725072 BY z i ATTORNEY May 15, 1951 R. H. BENSON ET AL SCAFFOLD WINCH Filed March 8, 1950 3 Sheets-Sheet 3 ATTORNEYS Patented May 15, 1951 S'CAFFOLD WINCH Robert H. Benson and Howard R. Benson, Concord, Tenn.

Application March 8, 1950, Serial No. 148,489

1 Claim. 1 This invention relates to winches or hoists. An object of this invention is to provide a winch which as an example may be used for scaffolds and which includes an improved safety means to prevent unwinding of the drum or reel when the crank is released.

Another object of this invention is to provide in a winch a combined ratchet and low speed operator for the reel, the combined ratchet and operator being in the form of 'a floating worm engageable with a wormgear which is fixed relative to the reel.

A further object of this invention is to provide a safety means of this kind-wherein the ratcheting 'worm may be manually shifted endwise to disengaged position with respect to the worm gear so that the reel may be freely rotated to unwind the cable therefrom.

A further object of this invention is to provide a relatively large reel gear of the spur type with a worm gear fixed to the reeland a shiftable crankshaft having a pair of gears thereon. One of the pair of gears is adapted to mesh with the large spur gear in one position of the crankshaft, and the other gear is adapted to mesh with a gear on a worm-shaft when the crankshaft is shifted endwise so that the reel can be rotated in either direction with the worm inherently locking the reel. In the neutral position of the crankshaft the worm will automatically lock the reel against unwinding when a load is imposed on the winch frame, but when the worm is manually disengaged from the worm gear the reel may be freely rotated ineither direction. The 'winch herein disclosed is particularly adapted for use in supporting scaffolding used by bricklayers wherein heavy loads are placed on the scaffolding and wheelbarrows are 'moved over the scaffolding.

In the drawings:

Figure l is a detailed front elevation of a winch orhoist constructed according to an embodiment of this invention.

Figure '2 is a detailed side elevation of the device.

Figure 3 is a fragmentary vertical section of the device.

Figure 4 is a fragmentary sectional view taken on the line 44 of Figure 3.

Figure 5 is a fragmentary sectional view taken on the line 55 of Figure 3 showing the worm gear in released position.

Figure 6 is a fragmentary sectional view taken on the line 6-6 of Figure 2.

" disposed on the upper side thereof.

-on a reel or drum 23.

through the ring or eye l3.

which has extending upwardly therefrom a pair of upwardly convergent bars I2 to the upper ends of which is secured a guide ring l3. The frame structure I0 also includes a pair of downwardly extending scaffold supporting bars l4 which, asshown in Figure 1, converge downwardly and are then bent in vertical position to form a U-shaped cross piece cradle I5; A connecting brace I6 is secured between the lower ends of the bars I l to hold these bars and the legs of the U-shaped member in spaced relation.

-A timber or cross piece I1 is adapted to engage through the U-shaped member 15 and is adapted to have longitudinal platfrom timbers The upper divergent ends of the bars M are secured to the lower ends of the legs of the U-shaped member ll by means of a pair of bolts 19 and I9, and

spacer members 29 and 2| engage about the 'bolts [8 and [9, respectively, and between the legs of the U-shaped member II.

A reel shaft 22 is journalled between the legs of the U-shaped member I l and has fixed there- One side of the reel or drum 23 is formed by a relatively large spur gear 24, and the other side of the reel or drum 23 is 'formed by a plate 25.

A cable 26 is adapted to be wound about the reel or drum 23 and is then extended upwardly A hook 21 is secured to the end of the cable 29 and is adapted to engage a suitable supporting'means 2B.

A crankshaft 29 is rotatably carried by bearings 39 and 3|, and theshaft 29 has fixed thereto a crank 32which is formed with a slidable and rotatable handle 33. The shaft 29 has fixed thereon a relatively small spur gear' 34 and has movement by means of a spring pressed ball 36 which engages in a selected one of the annular grooves 31, 38, and 39 which are formed in the shaft 29. When the ball 36 is engaged in the groove 31, gear 34 will be in mesh with spur gear 24 so that reel or drum 33 will be rotated from gear 34. When ball 36 is engaged in groove 38, gear 34 will be disengaged from gear 24, and shaft 29 will be in the neutral position. When ball 36 is engaged in groove 39, shaft 29 will be in its innermost position, and bevel gear 35 will be in mesh with a second bevel gear 49 which is fixed on a worm shaft 4|. The worm shaft 4| is journalled in bearings 42 and 43 which are fixed to the U-shaped frame H, and th shaft 4| has fixed thereon a worm 44.

The reel shaft 22 has fixed thereon a worm gear 45 which is adapted to be engaged by the worm 44. The shaft 4| is freely movable in an upward direction so that when the drum or reel 23 is being rotated through gears 34 and 24, shaft 4| with worm 45 will be raised upwardly and will ratchet on the teeth of worm gear 45. When gear 34 is released by release of crank 32 so that the load on cable 26 will tend to unwind from the reel or drum 23, the clockwise rotation of worm gear 45 will pull worm 44 and worm shaft 4| downwardly to a fully engaged position asshown in Figure 4. In this position of the worm 44, reel or drum 23 is positively locked against'unwindmg. I A's afurther safety means for holding reel or .drum 23 against unwinding a pivoted pawl '46 is carried by the frame I and engages large spur ".gear 24. The frame I I includes a loop or U-shaped mernber 41 which is fixed to one side of theframe fand is disposed at right angles to the U -shaped member l5 for supporting a hand railparallel to the boards orbeams which are mounted on the cross piece l1. I 7

' In the use and operation of this winch the scaffoldwhich as an example, is a scaffold for use by 'bricklayers, will be disposed close to the ground, In order to' provide a means whereby the, cable '26 may be unwound so that the hook 21 may be secured to the frame of the building 1 at" an elevated point, the crankshaft 29 is shifted endwise to the intermediate or neutral position with the ball 36 engaging in groove 38.' In this position of the crankshaft 29, gears 34 and'35 will be disengaged from their associated gears 24 and 4|], respectively. .At thistime dog or pawl46 ;will be raised from spur gear 24, andQshaft 4| .is manually moved upwardly so that worm44 "will be disengaged from worm gear 45. The disengagement of worm 44 from worm 45 may be readily effected by partially rotating reel 23 in a I winding direction to raise worm 44 and shaft 4| upwardly to the ratchet position. With worm 44 manually held upwardly to a position as shown in I Figure 5, cable 26 may be pulled through the ring or guide eye l3 until the cable is substantially unwound from reel 23. s

If desired, the winch including the frame may be laid fiat on the ground with the wormrshaft 4| uppermost so that this shaft will gravitatingly move downwardly to released position withrespect to the worm gear 45. The cable 26 may then be freely pulled from the reel 23..

,With the winch structure in a vertical position and the upper end of cable 26 secured to a suitable support, the scaffold may be raised by turning crank 32. At this time crankshaft 29 will .be disposed in the full lined position shown in Figure 3 with'ball 36 engaging in groove 31. Gear 4 a 34 will be in mesh with large reel gear 24. R0- tation of shaft 29 in a clockwise direction will effect rotation of gear 24 in a counterclockwise direction so that worm gear 45 will be constantly moving worm 44 and shaft 4| upwardly. The worm 44 will be constantly dropping downwardlyby gravity to engage the teeth of gear 45 so that in the event crank 32 is released at any time worm 44 will instantly lock worm gear 45 against rotation. The locking position of worm gear 45 is shown in Figure 4. As an added safety factor, handle 33' is slidable,

through the end of crank 32 and may be shifted inwardly to the dotted line position shown in Figure 1 whereinthe handle 33 will be in contact with one side of the frame I l. I

With spur gear 34 in mesh with spur gear 24 reel 23 can only be rotated to wind cable 26 thereon. In the event it is desired to unwind cable 26 from reel 23 with a load on the cable 26, crankshaft 29 is shifted inwardly until the ball Stengages in' groove 39. At this time bevel gear 35 will be engaged with bevel gear 49 of wormsh'aft 4|. Rotation of crankshaft 29 will thereupon effect rotation of Worm gear 45 and reel'23 in either a winding 0r unwindin direction. The worm and worm gear structure herein disclosed provides an irreversible lock for the reel shaft 22 so that this shaft will be automatically locked against rotation" in an unwinding direction when wormi44 is engaged with worm gear 45. A

What is claimed is:

A'winch comprising af' frame, a reel'rotat'ably carried by said frame; a spur gear fixed relative said first named gear, a worm shaftymeans carried by said frame rotatably mounting said worm shaft in substantially upright position, a worm on said worm shaft engageable with said worm gear, a bevel gear on said worm shaft, and a bevel gear on said crankshaft engageable with said first named bevel gear in another position of said crankshaft for rotating said reel in "either direction through said worm and worm'ge'ar, rotation.

of 'said reel in a winding direction throughsaid spur gears effecting endwise movement of said worm shaft whereby said worm will, ratchet on said worm gear. V, ROBERT I-I. BENSON.

HOWARD R. BENSON;

REFERENCES CITED The following references are of recordin the file of this patent:

UNITED STATES PATENTS Name "Date w Benson Mar. 6, 1934 Number 

